Apparatus for controlling the coating applied to an object



APPARATUS FOR CONTROLLING THE April 12, 1949. T. E. mm 2,466,734

COATING APPLIED TO AN OBJECT I Filed May 4, 1945 5-Sl 1e9ts-Sheet 1 .0Io o e I V o loll v u l j I! uvvszy rox. N By Tho/7211551 0; 519

April 12, 1949. T. E. PIAIZZE 2,46 3

.APPARATUS FOR CONTROLLING THE =COATING APPLIED TO AN OBJECT Filed May4, 1945 7 3 Sheets-Sheet 2 IN V EN TOR.

3 Sheets-Sheet 3 mmvron 1'. E. Pl'Azzlz APPARATUS FOR CONTROLLING THECOATING APPLIED TO AN OBJECT A ril 12; 1949.

Filed May 4, 1945 I Pia/ 6, BY

Patented Apr. 12,1949

APPARATUS FOR CONTROLLING COAT- lNG APPLIED TOAN OBJECT Thomas E. Piano,Mount Vernon,

Ohio, assignor, I

by mesne assignments, to Shellmar Products Corporation, Mount Vernon,Ohio, :1 corpora- .tion of Delaware Application May 4, 1945, Serial No.591,883 20mm. (on. 91-53) The present invention relates to improvementsin the industry of coating materials. More particularly, it pertains toa device for regulating and controlling'the application of viscouscoating solutions to moving objects, such as a rotating roller whichthereafter transfers the coating directly to a traveling web, or byregulating and controlling the coating solution after it has beenapplied to a web, by a combined operation of metering and evenlydistributing the metered solution to such moving objects, and theprovision of such a device is a principal ob- Ject of the invention.

It is generally known in' the coating industry that conventionalmechanical devices, used in the art of coating Webs such as paper,cellophane, and the like, with liquid materials of various viscosities,are not adaptable for obtaining coatings of a uniform thickness and asmoothness to a high degree'of accuracy. This isparticularly true, forexample, of devices employing rotating rollers and stationary bars as ameans for applying coatings of viscoussolutions. When rotating rollersare used for metering purposes, extreme accuracy of thickness almostbecomes an impossibility due to the fact that the non-controllableimperfections of the rollers, which are purely of a mechanical nature,reflect directly upon the film formation of thecoating solution on thewebs at the time of its application. Diflicultly controllable factorswhich contribute largely to inaccurate coatings involve, for example,eccentricity of the periphery of the roller surface which usually cannotbe held to less than .001". Also, circumferential crowding of the'coating material, in the form of ridges, is characteristic of viscousmaterials when applied to smooth faces of rotating rollers. Anotherfactor involved is uneven transfer of coating solutions from one rollersurface to an0ther,'or from a roller surface to a web, because thecoating material has a tendency to become stringy at the point where thesurfaces leave each other.

Several well known devices have been used in combination with coatingapplication methodsin attempts to overcome such difficulties anddisadvantages as the foregoing. As a rule, such devices consist ofstationary members, or so-called doctor blades, designed invarious-configurations. Most of these devices consist of highly smoothedand curved surfaces terminating in a. sharp edge over which the freshlycoated web is made to drag. The web is then deflected over the edge soas to apply a gentle amount of pressure. The sliding action of-theobjects against the smooth 2 sharp edge seems to flatten down thecoating to a smooth ,and even appearance, but these devices are, notcapable of-metering the coating to a. uniform thickness and'evendistribution over the entire web, or selected portions thereof.

Generally, it is an object of the invention to overcome the foregoingdifficulties and disadvantages and to provide a device which is economicof manufacture, simple yet sturdy and durable 'of construction, whichwill operate with comparative freedom from wear and tear, and is sodesigned as to afford a wide range of regulation and control of aviscous coating solution so that the same can be applied to a roller, orto a web, in a manner heretofore never accomplished, without seriousconcern of eccentricity of roller surfaces, unevenness and thickness ofpaper, vibration factors, or any other factors like those heretoforeenumerated which might be the cause for an uneven coating.

In its broader aspects the invention has for its object the provision ofa device, for regulating and controlling an amount of viscous coatingsolution applied to a moving object, which utilizes a'metering andsmoothing member along which the viscous material will flow with meansdisposed on the member which rest against the object to be coated whileholding the member in spaced apart position from the object to permitthe solution to flow, thereby metering the amount thereof to be appliedto the object, and means along which the viscous solution continues toflow after metering, whereby to smooth and spread the same into 'acoating of substantially even thickness against a moving object.

More specifically, the invention has for its object a device of theforegoing type which utilizes a relatively thin and flexible meteringand smoothing blade along which the viscous material will flow, theblade having a plurality of projections of substantially equal magnitudedisposed along the blade which rest against a moving object, such as arotating roller-or traveling web, and hold the blade in spaced apartposition from the object permitting the solution to flow and therebymetering the amount to be-applied' ,to the object, and an extensionportion on the solution is being applied to brace the web againstviscous solution which is permitted to flow between the coated objectand the blade.

Other objects of the invention will inpart be obvious and will in partappear hereinafter.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts, which will beexemplified in the construction hereinafter set forth and the scope ofthe application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the inventionreference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

Fig. 1 illustrates an elevational view of a metering and smoothing bladeas applied, for example, to a rotogravure applicator type of rollerbefore transferring a viscous coating to a traveling web;

Fig. 2 is a plan view of a fragment of a metering and smoothing blade ofthe type depicted inFig. 1;

Fig. 3 is a front elevational view of the blade portion shown in Fig. 2;

Fig. 4 is a transverse sectional View of the' blade taken along thelines 4-4 of Fig. 2;

Fig. 5 is an enlarged view of the metering and smoothing bladeillustrating its operation; Fig. 6 is an enlarged plan view of a portionof the bottom of such a blade illustrating the flow of viscous solutionalong and away from the same;

Depending upon the nature or the work to be done, the blade should beanywhere from .001 of an inch and over in thickness. The distancebetween dots can be anywhere from .010 of an inch to one inch, and eachprojection can be anywhere from .001 to .050 of an inch in thickness.

In Fig. 1 such a blade illustrates the manner in which a viscous.solution I 4 in a tank, or reservoir, I5 is metered and smoothed uponan applicator roller 16 operating on the rotogravure principle. Therotation of the roller causes the solution to flow along the bottom ofthe blade Fig. '7 is an end elevational view of a device I forcontrolling and regulating a blade such as that shown, in Fig. 1,illustrating the blade in operation directly against a traveling web;and

Fig. 8 is a front elevational View, partly in section and with partsbroken away, of the device illustrated in Fig. 7.

Referring more particularly to the drawings, there is shown a metering'and smoothing'blade 10 secured in a holder Ii. Such a. blade preferablyis made of a springy material of light thickness so as not to applyexcessive pressure. Transversely oi the blade I0 is a plurality ofprojections 12. Preferably, these projections are made by distortingsections of the blade to form beads, or buttons, which are generallycircular in cross section. It should be observed that these beads, orbuttons, are of substantially equal magnitude in the degree ofprojection from the top surface of the blade and that they are disposed'in substantially transverse alignment of the I0 and between theprojections I! because these projections, where they are in point ofcontact with then'oller l6, hold the blade in spaced apart relationshipwith respect to the roller, readily permitting the solution to flowunder the blade. By virtue of the arrangement and size of theprojections, a viscous solution can be metered in any amount desired.However, as more clearly illustrated in Figs. 5 and 6, the viscoussolution is permitted to sweep past the projections and against theextended portion I3 of the blade, the latter smoothing the solution inan equal distribution andeven thickness as it leaves the extreme edge Hof the blade 10.

When practicing the method of application shown in Fig. l, a travelingweb l8, such as paper, cellophane, or the like, is run against theapplied coating 19 between the nip of a pressure roller 20, and thecoating 19 is then tran ferred to the web; As soon as the coating leavesthe extended portion of the blade l3, where it has been smoothed andevenly distributed as illustrated in Fig. 6, the material is coated ontothe web surface in the same condition. There are no appreciable voids,spaces, irregularities, stringiness or the like, as so often is producedby conventional devices, and this results in a very desirableapplication of coating material of superior quality. This isparticularly noticeable where such webs, when transparent, are laminatedto similar webs. Conventional devices invariably apply coatings which,because of the various irregularities and imperfections, such as thoseabove mentioned, can readily be detected when such transparent laminatedWebs are held against light rays. Obviously, such improperly coatedsurfaces do not give maximum qualities of adhesion, moistureproofness,or whatever quality is desired for such coated webs. Particularly, inthe so-called duplex or laminated web, in addition to the fact that suchqualities are absent, there is an insufliciency of desirabletransparency characteristics, and the webs take on the appearance oftranslucency' rather than transparency. I It is to be noted that it iswithin the contemplation of the invention to cause the metering andsmoothing blade to be moved along a stationary object to be coatedalthough holding the blade stationary against a moving object ispreferable.

A smoothing and metering blade constructed in accordance with theprinciples of the present invention is particularly advantageous in thatit can readily be adjusted to regulateand control I practiced directlyupon a traveling web, illustrating the versatility of the coatingdevice. The same type of apparatus, of course, can be used to hold theblade in position against a roller as illustrated in Fig. 1. However,this device will be described in connection with the regulation andcontrol of a coating solution applieddirectly to a traveling web runningagainst a supporting roller.

In its preferred form the micrometric adjusting device comprises a mainshaft 2| journaled in bearings 22, 22, secured to the side frames of acoating machine 23, 23. At one end of this shaft is a worm wheel 24,meshed with a worm 25, on a shaft 26, under control of a hand wheel 21.Keyed to the shaft 2| is a two-part carriage, or header members, 28, 29,disposed adjacent each side frame, one header carrying a worm wheel 30keyed to a shaft 3|. The worm wheel 30 is meshed with a worm 32 on ashaft 33 under the control of a hand wheel 34. This train of gearsprovides the micrometric control for two gear segments 35, 35. Thesesegments are pivotally mounted at 36 and 31 on the two-part carriage, orheader members, 28, 29, respectively. The gear segments have gear teeth38 which mesh with splined or toothed portions 39, 39, on the shaft 3|Mounted between the toothed segments 35, 35, is a blade holder 40 whichholds blade ill in fixed position, either against an actuating rollersuch as that indicated at iii in Fig. 1, or against the web 4| in Fig.7. It will be observed that the web 4| is supported, for example, by aroller 42 disposed against the opposite surface of the web in the areawhere thesolution is to be applied to brace the web against the pressureof the blade.

It should be noted that the projections l2, on the blade l0, should bein line contact transversely of, and in contact with, the web 4|supported by the roller 42, and that the pivot points 38, 31, for thesegments 35, 35, are in axial alignment with the line of contact betweenthe object to be coated and the line of projections l2. The samecondition would, of course, obtain where the projections are in contactwith, for example, the applicator roller "5. This is of importance inregulating the micrometric control of the device because the blade cannow be tilted around the projections utilizing them as pivot points. Itwill be seen that the tilting of the blade I0 about the projections |2enables an operator to regulate the flow of viscous solution which fiowsunder the blade to an object in motion, such as the web 4|, or theroller I6, by rocking the blade toward or away from the object at thepoint where the solution begins to flow to the projections. The distancewhich the projections space the blade, from either the web or a roller,will meter or control the amount of solution which is permitted to fiowto the surface to be coated. By turning the hand wheel 34 the segments35, 35, can gradually be swung in either direction so as to control theseparate smoothing action of the extension l3 of the blade ID to anydegree required.

In order rapidly to move the blade into and out of operating position,the hand wheel 21 is utilized to turn the shaft 26, worm 25, and wormwheel 24.

The actual finishing action of the coating aperation occurs at themoment when the material leaves the edge ll of the blade which reducesto a minimum the hazards of stringing, irregularities, unevendistribution, and other disadvantageous characteristics.

It will thus be seen that the objects hereinbefore set forth may readilyand efliciently be attained. and since certain changes may be made inthe above article and different embodiments of the invention could bemade without departing from the scope thereof, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. In a, device for regulating and controlling an amount of viscouscoating solution applied to a moving object, the improvement comprisinga relatively thin and fiexible metering and smoothing blade along whichsaid viscous material will flow, a plurality of projections ofsubstantially .equal magnitude disposed transversely along said tion onsaid blade constituting the section directedbeyond said projections tosaid terminating edge along which said solution will continue to flowafter the same has been metered by said pro-'- jections, thereby tosmooth and spread the same into a coating of substantially equaldistribution and thickness against said object.

2. In a. device for regulating and controlling an amount of viscouscoating solution applied to a moving object, the improvement comprisinga relatively thin and flexible meteringand smoothing blade along whichsaid viscous material will fiow, a plurality of projections ofsubstantially equal magnitude disposed transversely along said blademarginally inwardly from its terminating edge, to rest against saidobjectand to hold said blade in spaced apart relation with respect tosaid object to permit said solution to flow therebetween and thereby tometer the amount thereof to be applied to said object, andan extensionportion on said bladeconstituting the section directed beyond saidprojections to said terminating edge along which said solution willcontinue to flow after the same has been metered by said projections,thereby to smooth and spread the same into a coating of substantiallyequal distribution and thickness against said object, a holder tosupport said metering and smoothing blade in contact with said object tobe coated, and means to tilt said blade about said projections whileusing the latter as a fulcrum point, thereby to regulate and control theamount of said solution which is permitted to flow upon said object.

THOMAS E. PIAZZE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 491,861 Smith et a1. Feb. 14,1893 1,799,002 Case Mar. 31, 1931 2,024,284

Grower Dec. 17, 1935

